Concrete building block



1. Concrete building block

FIG. 1.1 is a perspective view of a concrete building block;

FIG. 1.2 is a front view thereof;

FIG. 1.3 is a back view thereof;

FIG. 1.4 is a top view thereof;

FIG. 1.5 is a bottom view thereof;

FIG. 1.6 is a right side view thereof;

FIG. 1.7 is a left side view thereof; and

FIG. 1.8 is a cross-sectional view thereof taken along line 1.8 in FIG. 1.2.

The broken lines shown in FIGS. 1.1-1.8 illustrate portions of the concrete building block that form no part of the claimed design. 

CLAIM The ornamental design for a concrete building block, as shown and described. 